Digitizer sensors are used for touch detection in many Human Interface Devices (HID) such as laptops, track-pads, MP3 players, computer monitors, and smart-phones. A touch-screen is a Flat Panel Display (FPD) integrated with a digitizer sensor. A grid based capacitive sensor is one type of digitizer sensor. Grid based capacitive sensors typically track free style input provided with an object such as a finger or a conductive object with a mutual capacitive or self-capacitive detection method. A grid based capacitive sensor may also be used to pick up signals emitted by a stylus and thereby track position of the stylus. Coordinates of the tracked object may be reported to the HID. Some active styluses emit a signal that includes information. A circuit associated with the grid based capacitive sensor may decode and report the information to the HID.